1. Lead in Cathode Ray Tube and solder.
2. Arsenic in older Cathode Ray Tubes.
3. Antimony trioxide as flame retardant.
4. Polybrominated flame retardants in plastic casings, cables and circuit boards.
5. Selenium in circuit boards as power supply rectifier.
6. Cadmium in circuit boards and semiconductors.
7. Chromium in steel as corrosion protection.
8. Cobalt in steel for structure and magnetivity.
9. Mercury in switches and housing disposing of computers becoming a global concern.